1. Place tofu on paper towels; cover with paper towels. Top with a heavy skillet; let stand 30 minutes. Discard towels. Cut tofu into 1-inch cubes.
2. Combine Sriracha and the next 3 ingredients. Combine broth and next 3 ingredients, stirring until smooth.
3. Heat canola oil in a large skillet over medium-high heat. Add beef; stir-fry 3 minutes. Add garlic and ginger; stir-fry 30 seconds. Add Sriracha mixture; cook 1 minute, stirring occasionally. Add broth mixture; bring to a boil. Cook 1 minute. Stir in tofu. Serve with rice and Broccolini; sprinkle with cilantro.